Olive oil – described as “liquid gold” in Homer’s Iliad – is renowned for its health benefits. Not only is it delicious, it is anti-inflammatory, good for the gut, beneficial for the heart, and may even help us feel happier and live longer.

Scientists are now turning their attention, however, to the murky, brown and previously discarded by-product of its production – olive mill wastewater (OMW) – and have discovered it may be an even more powerful superfood.